APG stocks the SV70272, an AS568-272 black Viton® (FKM) 70 Shore A Square-Cut Ring measuring an inside diameter of 9.484 in (240.89 mm), a cross section of 0.139 in (3.53 mm), and an outside diameter of 9.762 in (247.95 mm). A square-cut ring resists the spiral failure that affects round rings on long reciprocating strokes.
Viton® (FKM) is specified here for industry benchmark where nitrile reaches its thermal limit and very low compression set at elevated temperature. This material stands up to many acids, aggressive chemicals, and engine and transmission fluids. Published continuous service range is -15°F (-26.1°C) to 400°F (204.4°C). Exposure to amines or low-molecular-weight organic acids will shorten service life. The profile itself contributes greater resistance to extrusion than a round section of the same size and a rectangular section that will not roll in the groove. Note that a square section is less suited to high-speed rotary service, where the larger contact area raises friction and heat.
Typical settings include chemical processing, semiconductor equipment, and oil and gas.
This item is sold individually under part number SV70272. Nominal inside diameter is listed as 9 1/2 inch. Confirm chemical compatibility, pressure and temperature against your own application requirements before installing.
Description -272 BLACK FKM 70D SQUARE RING
Actual Cross Section 0.139 inch (3.53 mm)
Actual Inside Diameter 9.484 inch (240.89 mm)
Actual Outside Diameter 9.762 inch (247.95 mm)
Measurement System Imperial
Product Category O-Rings - Square/Quad - Commodity